#include #include #include #include #include #include #include "sock.h" #include "die.h" #include "str.h" #include "built_in.h" int af_socket(int af) { int sock; if (unlikely(af != AF_INET && af != AF_INET6)) panic("Wrong AF socket type!\n"); sock = socket(af, SOCK_DGRAM, 0); if (unlikely(sock < 0)) panic("Creation AF socket failed!\n"); return sock; } int pf_socket(void) { int sock = socket(PF_PACKET, SOCK_RAW, htons(ETH_P_ALL)); if (unlikely(sock < 0)) panic("Creation of PF socket failed!\n"); return sock; } void set_sock_prio(int fd, int prio) { int ret, val = prio; ret = setsockopt(fd, SOL_SOCKET, SO_PRIORITY, &val, sizeof(val)); if (unlikely(ret)) panic("Cannot set socket priority!\n"); } void set_nonblocking(int fd) { int ret = fcntl(fd, F_SETFL, fcntl(fd, F_GETFD, 0) | O_NONBLOCK); if (unlikely(ret < 0)) panic("Cannot fcntl!\n"); } int set_nonblocking_sloppy(int fd) { return fcntl(fd, F_SETFL, fcntl(fd, F_GETFD, 0) | O_NONBLOCK); } void set_socket_keepalive(int fd) { int ret, one = 1; ret = setsockopt(fd, SOL_SOCKET, SO_KEEPALIVE, &one, sizeof(one)); if (unlikely(ret)) panic("Cannot set TCP keepalive!\n"); } void set_tcp_nodelay(int fd) { int one = 1; setsockopt(fd, IPPROTO_TCP, TCP_NODELAY, &one, sizeof(one)); } int set_ipv6_only(int fd) { int one = 1; return setsockopt(fd, IPPROTO_IPV6, IPV6_V6ONLY, &one, sizeof(one)); } int set_reuseaddr(int fd) { int ret, one = 1; ret = setsockopt(fd, SOL_SOCKET, SO_REUSEADDR, &one, sizeof(one)); if (unlikely(ret < 0)) panic("Cannot reuse addr!\n"); return 0; } void set_mtu_disc_dont(int fd) { int mtu = IP_PMTUDISC_DONT, ret; ret = setsockopt(fd, SOL_IP, IP_MTU_DISCOVER, &mtu, sizeof(mtu)); if (unlikely(ret)) panic("Cannot set MTU discovery options!\n"); } enum { sock_rmem_max = 0, sock_rmem_def, sock_wmem_max, sock_wmem_def, }; #define SMEM_SUG_MAX 104857600 #define SMEM_SUG_DEF 4194304 static const char *const sock_mem[] = { [sock_rmem_max] = "/proc/sys/net/core/rmem_max", [sock_rmem_def] = "/proc/sys/net/core/rmem_default", [sock_wmem_max] = "/proc/sys/net/core/wmem_max", [sock_wmem_def] = "/proc/sys/net/core/wmem_default", }; static int get_system_socket_mem(int which) { int fd, val = -1; ssize_t ret; const char *file = sock_mem[which]; char buff[64]; fd = open(file, O_RDONLY); if (fd < 0) return val; ret = read(fd, buff, sizeof(buff)); if (ret > 0) val = atoi(buff); close(fd); return val; } static void set_system_socket_mem(int which, int val) { int fd; const char *file = sock_mem[which]; ssize_t ret; char buff[64]; fd = open(file, O_WRONLY); if (fd < 0) return; memset(buff, 0, sizeof(buff)); slprintf(buff, sizeof(buff), "%d", val); ret = write(fd, buff, strlen(buff)); ret = ret; close(fd); } void set_system_socket_memory(int *vals, size_t len) { bug_on(len != 4); if ((vals[0] = get_system_socket_mem(sock_rmem_max)) < SMEM_SUG_MAX) set_system_socket_mem(sock_rmem_max, SMEM_SUG_MAX); if ((vals[1] = get_system_socket_mem(sock_rmem_def)) < SMEM_SUG_DEF) set_system_socket_mem(sock_rmem_def, SMEM_SUG_DEF); if ((vals[2] = get_system_socket_mem(sock_wmem_max)) < SMEM_SUG_MAX) set_system_socket_mem(sock_wmem_max, SMEM_SUG_MAX); if ((vals[3] = get_system_socket_mem(sock_wmem_def)) < SMEM_SUG_DEF) set_system_socket_mem(sock_wmem_def, SMEM_SUG_DEF); } void reset_system_socket_memory(int *vals, size_t len) { bug_on(len != 4); set_system_socket_mem(sock_rmem_max, vals[0]); set_system_socket_mem(sock_rmem_def, vals[1]); set_system_socket_mem(sock_wmem_max, vals[2]); set_system_socket_mem(sock_wmem_def, vals[3]); } oremode:
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authorPaul E. McKenney <paulmck@linux.vnet.ibm.com>2016-06-15 16:08:17 -0700
committerIngo Molnar <mingo@kernel.org>2016-06-17 09:54:45 +0200
commitebff09a6ff164aec2b33bf1f9a488c45ac108413 (patch)
tree4c2e43caeacbd254daa8439564e991b1de82750c /Documentation/i2c
parentb316ff783d17bd6217804e2e4385ce9347d7dad9 (diff)
locking/Documentation: Clarify limited control-dependency scope
Nothing in the control-dependencies section of memory-barriers.txt says that control dependencies don't extend beyond the end of the if-statement containing the control dependency. Worse yet, in many situations, they do extend beyond that if-statement. In particular, the compiler cannot destroy the control dependency given proper use of READ_ONCE() and WRITE_ONCE(). However, a weakly ordered system having a conditional-move instruction provides the control-dependency guarantee only to code within the scope of the if-statement itself. This commit therefore adds words and an example demonstrating this limitation of control dependencies. Reported-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: corbet@lwn.net Cc: linux-arch@vger.kernel.org Cc: linux-doc@vger.kernel.org Link: http://lkml.kernel.org/r/20160615230817.GA18039@linux.vnet.ibm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'Documentation/i2c')